Fuze



F. B. HALE May 20, 1947.

FUZE

Filed May 3l, 1944 2 Sheets-Sheet l a. ,M p

2 Sheets-heet 2 F. B. HALE May 20', 1947.

h. L V m 2- w Lil En ml Patented May 2G, 1.947

UNITED STATES PATENT OFFICE 6 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government, for governmental purposes, without the payment to me of any royalty thereon.

This invention relates generally to al1-way fuzes for incendiary bombs, grenades, and similar munitions requiring an impact detonatedfuze.

Incendiary bombs released from airplanes often impact at an angle that is beyond the limits of the functioning of a point detonating fuze, thus the bomb does not explode. The positions of hurled grenades on impact are even more irregular.

An object, therefore, of the invention is to devise novel means for automatically bringing the firing pin in a fuze from a locked position for safe handling to an armed position after a bomb containing the fuze has been released from an airplane, so that it functions in any position when the bomb impacts on the target, the fuze being exceedingly simple in construction, positive and reliable in action, and very compact so as to reduce its space requirement.

A further object is to provide an impact fuze which is versatile in being adapted for use in many types of munitions and which functions properly when installed in various parts of theV munitions.

With these objects in View, an embodiment of the invention resides, generally stated, in an assembly of a firing pin or striker locked in a sleeve containing a primer and this assembly being supported in a hollow cylindrical body having inside conical end surfaces, until a primary safety or arming pin projecting into the head end of the body is sprung away from its unarmed position leaving the assembly free to move as an unattached unit inside the fuze body. When a bomb containing the fuze is placed in a cluster, a pull Wire normally holding the primary safety pin is removed, the safety pin is held in place by pressure from an adjacent bomb in the cluster. When the bombs fall from the airplane and separate the safety pin is thrown out by a spring, thus unlocking the firing pin and sleeve. On impact in any position, the firing pin is forced forward to strike the primer in the sleeve.

The accompanying drawings illustrate exemplary embodiments of the underlying principles of the invention.

Briefly described:

Fig. 1 is a sectional view taken on the longitudinal axis of one type of the all-way fuze showing the relation of the parts of the fuze prior to the clustering of the bombs on which it is mounted.

Fig. 2 is a sectional view showing the relation of the parts when the bombs are clustered.

Fig. 3 is a sectional view showing the relation of the parts in liring position.

Fig. 4 is a sectional view showing the relation of the parts on impact with the target.

Fig. 5 is a top View.

Fig. 6 is a sectional view taken on the longitudinal axis of still another type of the all-way fuze found particularly advantageous for use in an incendiary grenade or fuel tank igniter.

Fig. 7 is a sectional side view of an incendiary thermit igniter showing the all-way fuze of the type depicted by Fig. 6 located in the head of the igniter.

Fig. 8 is a top view of the igniter.

Fig. 9 is a sectional View taken on the longitudinal axis of still another type of the all-Way fuze particularly adapted for insertion vertically into a nose plug of a chemical bomb.

Fig. 10 is an end view of a fuze of the type shown in Fig. 9.

Referring more particularly by numerals to drawings in which the same and similar elements are designated by like symbols of reference throughout and more especially to Fig. 1 there is shown the fuze comprising a cylindrical body I, one end of which is bored to a conical surface 2 and threaded at 3, with the opposite end bored t0 a flat surface il and threaded at 5, a smaller bore 6 connects the bored cavities. In the cavity on corneal surface 2 rests sleeve l' that is bored to receive primer B and enlarge adjacent thereto for holding firing pin spring 9 and firing pin I6. Firing pin l!) is bored for locking pin l l and locking pin spring l 2. A longitudinal bore in firing pin lil receives safety pin I3 which restrains locking pin il. Head I4 is threaded at l5 for retaining the fuze in the bomb. Head ld has a conical surface IB and is attached to body I by thread 3. It is bored for safety pin I3, and with spring Il, the pin is retained by safety wire i8. In bodyv l, a plug I9 is screwed on thread 5. The upper portion of plug i9 has a groove 20 and is also bored for time fuze 2 i, below which a flash powder cavity 22 is closed by Celluloid cap 23.

The operation of this invention may be readily understood by rst having reference to Figs. 1 and 2 wherein the fuze is shown with the parts completely in unarmed relation. The firing pin i0 is locked in sleeve 1 by locking pin Il, thus preventing any movement between the ring pin and sleeve 1. Locking pin il is retained in this position by safety pin I3 and secured in the fuze by safety wire I8. With the parts in this position the fuze is assembled to the incendiary bomb. As the bombs 2d, Fig. 2, are placed one on another in clustering, the safety wire is pulled from the lower bomb, the upper bomb preventing safety pin I3 from ejection by safety pin spring I'I. The incendiary bombs dropping from an airplane become separated and allow safety pins I3, Fig. 1, to be ejected by safety pin springs I'I. With the removal of this obstruction in the firing pins IIB, locking pins II (Fig. 3) are moved over by the force of locking pin springs I2, disengaged sleeves l, thus allowing free movement of firing pins ID except for the pressure of firing pin springs 9.

The pressure of firing pin spring 9 on firing pin I presses it against conical surface Iii. The shock incident to the impact considering impact with the fuze in a vertical position, overcomes the pressure of firing pin spring 9 by reason of the inertia of the weight of firing pin Ill and thereupon strikes primer 8. In a reverse position, the same thing is accomplished by movement of sleeve 'I, with primer 8, against firing pin It. Impacting at any angle from the vertical center line of the fuze, the inertia of the weight of firing pin I0 (Fig. 4) and sleeve 'I causes them to slide on conical surfaces 2 and I, forcing ring pin I0 to compress ring pin spring 9 and strike primer 8. The flash of primer 8 through groove 2li ignites delay fuse 2| and in turn ignites flash powder in cavity 22 and Celluloid cup 23 thus igniting the main charge not shown.

The fuze illustrated in Fig. 6 is similar in construction and operation to the fuze described with reference to Fig. 1. It differs mainly in being a quick-acting fuze adapted for use in grenades and fuel tank igniters. The primer is pressed into the cup 8, and when the primer is subjected to the percussion by the pointed projection of striker I0, it flashes back through the bore t which is normally covered by a thin water-proof tape.

In Fig. 7 the fuze illustrated in Fig. 6 is shown assembled in a small grenade-like incendiary adapted for use as a fuel tank igniter. This type of munition has been perfected for installation in extra fuel tanks carried by aircraft, so that when these tanks are empty and released, they become exploded by the igniter on impact with the ground regardless of the position in which they land.

The igniter has a metallic casing 25 molded or formed from metal, such as steel, magnesium, or aluminum. It is charged with a pressed-in charge of thermit mixture 2E formulated, for example, from granulated aluminum, grained aluminum, iron oxide scale, barium nitrate and sulfur, also, with a first fire mixture '2l which may comprise magnesium powder and barium chromate. A pad 23 of wool hunting or cotton cloth impregnated with a readily ignitable material such as match composition, is placed at the surface of the first iire charge 2T. The all-ways fuze is screwed at head I into the open threaded end of the case 25.

At several points in the casing between the fuze I and the charge are drilled vent holes 3i] for allowing the escape of combustion gases from the burning charge. These vent holes normally have plugs 29 inserted of a material such as cork, and the plugs are blown out after the incendiary begins to function.

For satisfactory attachment to a fuel tank which is to become exploded, the casing 25 is provided with a iiexible gasket 32 made of Neoprene, or the like, held in place at the top of the igniter by a threaded nut 3l. The igniter may be inserted into a tank at its filling opening with the gasket 32 making an air-tight seal after the cover of the filling hole is tightened into position,

When the igniter is placed into a fuel tank that is to be released and exploded, the arming wire IIB is withdrawn, and thereupon, the arming pin I3 is ejected so that the igniter is armed and ready to cause the burning of the incendiary upon impact of the tank.

The fuze illustrated in Fig. 9 is also similar in construction and operation to the fuze described with reference to Figs. l to 5. In a self-contained unit it has percussion primer in cup B, a delay spitter fuZe 2l which receives the flash back from the primer cup 8, and a booster charge 22 which in turn is ignited by the delay sptter fuze. The delay spitter fuze charge 2| may comprise black powder in rolled lead and have a match composition closing both ends. The cellulose nitrate booster cup y23 containing fuze powder is cemented to the fuze case i and is reinforced into place by anged Zinc band 33. The head of the fuse Ill has inset holes 3d for insertion of wrench prongs in assembling and tightening the head to the body of the fuZe.

As another modification in the construction of the fune shown in Fig. 9, the arming pin acute a release pin 35 which slides within a retainer 3a? when the arming Wire I8 is withdrawn. With this construction, arming pin I3 is not entirely ejected from the fuze upon arming but becomes recessed within the head I and the hollow portion of retainer 36.

The fuze shown in Fig. 9 is particularly adapted for use in various chemical bombs, particularly tail ejection bombs designed to have the fuze occupy a small space in their nose portions. With the bombs clustered and with the arming wires I8 removed, the fuze is prevented from arming so long as the end of an adjacent bomb depresses the release pin 35, or so long as a release bar at the end of the cluster holds the release pin in place for the end bombs.

It is evident that the all-ways fuze provided by the present invention has substantially perfected flexibility with respect to positioning of the iuze in any desired part of a munitio-n.

Ihe mechanism of the fuze may be said to neat in a hollow cylindrical chamber having tapered or curved end surfaces, the end surfaces beingr approximately conical, parabolic, or still more rounded. When the fuze is armed, the primer holding sleeve 'I coupled with the striker II] are securely locked and restrained from any movement by both the position of the arming pin I3 and the locking pin II. The arming pin is conveniently aligned with the longitudinal axis of the fuze Vand projects axially into the striker wherein it prevents movement of the mechanism; and so long as the arming pin I3 is in the unarmed position, the locking pin II positively prevents the striker I@ from sliding toward the primer 8. When the arming pin i3 is ejected from the striker I9, the interlocking safety pin I I is released and becomes fully contained within the striker I 0 so that the mechanism is in a potential floating position free to gyrate about both longitudinal and latitudinal axes to the extent that the outer ends of the coupled primerholding sleeve and the striker I0 are able to slide over the tapered end surfaces within the fuze.

If a munition impacts with its fuze in a vertical position, the inertia of the striker I overcomes the resistance of spring 9 and is driven against the primer cup 8, If the munition falls in such a manner so that the fuze on impact is in an oblique or horizontal position, thecoupled striker and sleeve mechanism tends to gyrate into a, po-

sition in which the striker I0 is also forced toward the primer cup, the mechanism being telescopically collapsed as the outer ends of the striker I0 and the sleeve l become forced together in riding on the cam-like end surfaces, I6 and 2.

Fuzes made in accordance with the preceding set forth, have been found by practical tests to function properly and with the following'summarized results:

(a) Positive safety with sure functioning in all positions;

(b) Satisfactory action in a large variety of bombs, grenades, projectiles, and other munitions; Y

(c) Suitability for location in any desired part of a munition;

(d) Satisfactory functioning in combination with a time fuze;

(e) Suitability for clustering;

(f) Suitability for manufacturing and assembling with desired compactness.

There is accomplished by this invention a fuze which affords the safe transportation and handling of incendiary bombs on which it is mounted, protected against inadvertent operation prior to use, being positively locked and unaifected by shocks or movement, functioning only when the locks have been removed by releasing the bomb from an airplane.

While the described fuze assemblies exemplify preferred embodiments, it is to be understood that the invention is not confined to the precise details of construction herein set forth by way of illustration, as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invention or exceeding the scope of the appended claims.

I claim:

1. A fuze adapted to function at all angles of impact, comprising, Within an elongated hollow body interiorly having conical end surfaces, a primer-holder slidably coupled to a striker with ends resting normally at apices of the conical end surfaces, a locking pin plunger normally protruding through a side of the striker for locking the striker against movement toward a primer in the primer-holder, an arming pin extending through the apex of one conical end surface into the striker to hold the striker and primer-holder in their normalunarmed position while locking the locking pin in its normal position, and a coiled spring resisting movement of the striker toward the primer when the fuze is armed until adequate impact imparts an overcoming force to effect movement of the striker and primer-holder within the hollow body.

2f. An all-way fuze, comprising a body having inside cylindrical side walls and concave ends, a primer-charge holder acting as a guide for a plunging movement of a striker toward a primer charge, a safety pin locking the striker against the plunging movement, a spring pressing against the safety pin to force it into a recess within the striker when the fuze is armed to thereupon allow the plunging movement of the striker, and an arming pin extending from an end of the body 6 into the striker to hold the safety pin in a locked position While it holds the striker and primer charge holder in a central position between the cylindrical side walls.

3. An all-Ways fuze adapted to be fixed in a bomb, comprising a body enclosingan elongated cylindrical chamberwith tapered end surfaces, a ring mechanism assembly of a striker coupled to a primer charge holder resting with its longitudinal axis substantially coinciding with the longitudinal axis of the chamber, the ring mechanism assembly being free to gyrate about its latitudinal and longitudinal axes when the fuze is armed to the extent that its ends are able to slide over the tapered end surfaces of the chamber with the result that the striker is forced in the direction of a primer charge in the holder, an arming pin extending longitudinally into the ring mechanism assembly in its normal unarmed position wherein the striker is furthest separated from the primer charge, a safety pin mounted transversely in the striker so that it is obstructed from movement by the arming pin in the unarmed position, a recess in the striker for receiving the safety pin when it is unlocked by ejection of the arming pin, and a spring in the assembly for pressing the safety pin into said recess to thus release the striker for movement in the direction of the primer charge.

4. An all-ways fuze unit comprising a body member hollowed to form a chamber having cylindrical side walls and a conical bottom surface, a head member in threaded engagement with the body member closing the chamber with a conical top surface, a firing mechanism assembly of a striker having an outer end seating on the conical top surface and with a firing pin end guided by a primer holding sleeve having an outer end seating on the conical bottom surface, the outer ends of the assembly being free to slide in contact with their respective conical seating surfaces when the fuze is armed, a spring in the firing mechanism repressing the striker away from the primer in the sleeve, a safety pin in the firing mechanism assembly locking the striker away from the primer in the sleeve when the fuZe is unarmed, a central longitudinal bore in the head member for guiding an arming pin, an arming pin slidably inserted through the bore of the head member into the ring mechanism assembly for holding the safety pin in a locked position, a spring pressing against the arming pin to eject it from the ring mechanism assembly in arming the fuze, a bore in the sleeve of the ring mechanism assembly for passage of a flash from the primer, and a detonating charge holder attached to the body member to receive a flash passed from the primer through the bore in the sleeve.

5. A fuze adapted to function at all angles of impact, comprising an elongated body having a substantially hexagonally recessed portion, an assembly in said body of a primer holding sleeve telescopically coupled to a striker having an elongated recessed portion therein, a spring within said sleeve pressing against said sleeve and said striker, a resiliently and inwardly pressed locking pin slidably and radially mounted in said sleeve and in said striker and extending to the recessed portion of said striker, said assembly being an unattached unit free to move inside the recessed portion of said body When the fuZe is armed and being provided with an elongated spring-pressed arming member projecting into the recessed portion of the striker from the head of the fuze and against the spring pressure to hold the locking pin in the sleeve, and a detachable locking means Afor lockingand releasing the arming member in said striker.

6. A fuze, comprising a recessed body having a longitudinally extending and substantially hexagonally shaped recessed portion therein, an assemVA bly in said body free to move inside the recessed portion of said body, including a primer-holding sleeve, and a striker provided with an elongated recessed portion telescopically coupled together, a compressed spring Within said sleeve between the sleeve and the striker, a locking pin radially and slidably mounted in said sleeve and said striker and extending into and being spring pressed toward the recessed portion of said striker, a spring-pressed arming member extending into the recessed portionV of said striker against spring pressure and a detachably mounted locking means for retaining the arming member in said recessed portion of the striker when the fuze is unarmed and adapted to release the striker when the arming member is withdrawn from the fuze.

FRANK B. HALE.

The following references Vare of record inthe ille oi this patent: 

